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Red zone............................................................................ 5
BI016912-04 (EN-US)
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Red zone
Remote controlled continuous miners
The remote control of miners introduces certain potential safety hazards which the miner operator must watch for and be aware of. While the operator is now free to position himself for convenient visibility of mining operations at the face, he can easily expose himself to the danger of being near mobile heavy equipment.
Most significantly, the operator’s greatest danger is from his Continuous Miner, especially when he is maneuvering it during mining operations. The miner is capable of slewing when turning, especially when the crawlers are split. The discharge conveyor can also swing. In each of these cases, the miner operator is in danger of being hit, or worse yet, run over by his own machine. Equally dangerous is the possibility of the operator being pinned against the rib by his own miner.
Miner operator danger areas, or Red zones
Some typical situations dangerous to the miner operator are illustrated on the following pages. The danger area, or red zone (Fig. 30) is indicated by alternating red and white diagonal stripes.
Fig. 30: Red zone
Tramming the miner (Fig. 31) from one place to another, especially maneuvering around intersections. This illustrates that the operator should not place himself between his miner and the rib.
Beginning the first sump (Fig. 31) in a new cut. The miner is against the left rib and the discharge conveyor is swung toward the center of the entry ready for the haulage car. The operator must stay clear of the discharge conveyor and the rear of the miner.
Fig. 31: Red zones
Tramming the miner red zone Beginning 1st sump red zone
Sumping in the left hand side of the cut (Fig. 32). As the miner penetrates the face, new unsupported roof is being exposed, and the operator now has an additional constraint to his movements. He must also stay clear of the haulage vehicle at the rear of the miner as it approaches the miner and while it is loading.
Repositioning the miner for the right hand cut (Fig. 32). Because the miner is backing out and turning in close quarters, the operator must stay behind the miner to be safe.
Sumping in the right hand cut (Fig. 32). Again, the operator must stay away from the face where the newly-exposed roof is unsupported, as well as staying clear of the haulage vehicle while it approaches and loads.
BI016912-04 (EN-US)
Fig. 32: Red zones
Sumping on the left hand side red zone
Sumping in the right hand cut red zone Repositioning miner for right hand cut red zone
Crosscut red zones (Fig. 33). Beginning and completing crosscuts requires a lot of maneuvering of the miner and loading the haulage vehicle while at awkward positions. Crosscuts also result in newly exposed unsupported roof. Respecting a red danger zone is important to operator safety in these conditions.
When the miner beginning a right hand crosscut it is nearly against the opposite (left hand) rib, while the discharge conveyor is swung to its maximum 45o right position for loading the haulage vehicle. Hence, the entire rear of the miner is treated as a red zone. There are two other danger areas. On the right hand side, the miner forms a pinch point at the rib which must be avoided. Also, on the left hand side of the miner, as the miner progresses into the rib, a sharp-angled fender will be formed which will be susceptible to sloughing and falling off. Hence, that rib must be considered a red zone.
The red zone surrounds the miner as the discharge conveyor is free to swing either way and more unsupported roof is exposed during the further development of the right hand crosscut.
Fig. 33: Crosscut red zones
Beginning a right hand crosscut red zone Right hand crosscut development
Pillaring red zones (Fig. 34) Remote control offers a significant safety advantage in partial or complete removal of the pillars in retreat mining because it places the operator further away from potential collapsing roof.
Much of the area around the miner must be considered a red zone, mostly because of extensive unsupported roof and the need for temporary supports under weakened roof. With remote control, the operator can position himself safely away from the miner while still retaining a good view of the mining cycle.
A red zone around the miner is no longer applicable when working in the opposite right hand pillar, as the operator is now excluded from the entire working area because of failing roof considerations, even with the existence of temporary roof supports.
When making an additional end cut into the pillar, creating a fender of coal between the two cuts, additional temporary roof supports are installed.
Because of roof pressures, the fender will tend to slough its ribs in the process of eventually crushing. Hence, the operator must stay away from this fender as well as avoiding the entry and crosscut areas as shown.
Fig. 34: Pillaring red zones
Pillaring in a left hand cut red zone Pillaring in a end cut red zone Pillaring in a right hand cut red zone
